Physical Sciences and Mathematics Commons^™

A Study Of 3-Tropylium-1,5-Hexadiene, Elise Noma Hattersley

Dissertations, Theses, and Masters Projects

No abstract provided.

The Analysis Of Plasmid Conformers Using Dynamic Size-Sieving Capillary Electrophoresis, Stacey Nevins

Dissertations, Theses, and Masters Projects

No abstract provided.

Biogeography Of Amphi-Atlantic And Amphi-American Fishes: The Scomberomorus Regalis (Scombridae), Strongylura Marina (Belonidae) And Hyporhamphus Unifasciatus (Hemiramphidae) Species Groups, Heidi M. Banford

Dissertations, Theses, and Masters Projects

Phylogenetic and historical biogeographic hypotheses were explored for three groups of teleost fishes that are hypothesized to share a common biogeographic track. Distributed across the eastern Pacific/eastern Atlantic (EP/EA) biogeographic track of Rosen (1975) are the Scomberomorus regalis (Scombridae), Strongylura marina (Belonidae) and Hyporhamphus unifasciatus (Hemiramphidae) species groups comprised of one eastern Atlantic; three, three and four western Atlantic; and two, two and four eastern Pacific species, respectively, for each group. In addition, two species in the Strongylura marina and Hyporhamphus unifasciatus groups, have invaded freshwater drainages of Central and South America. Each of the three species groups were found …

Interactive Effects Of Cadmium And Benzo(A)Pyrene In Mummichog (Fundulus Heteroclitus), Peter Van Den Hurk

Dissertations, Theses, and Masters Projects

When animals are exposed to mixtures of environmental pollutants, it is generally assumed that the toxic effects of the individual components are additive. However, examples of synergistic and antagonistic effects have been described. to study the mechanisms of interaction between a metal and a polycyclic aromatic hydrocarbon, mummichog (Fundulus heteroclitus) were injected with combinations of cadmium (Cd) and benzo (a) pyrene (BP). Measured effect parameters were: mortality, BP-metabolite production in isolated hepatocytes and microsomes, hepatic induction of CYP1A (the BP metabolizing enzyme) and metallothionein (the Cd binding protein), and biliary excretion of BP-metabolites. The mortality data demonstrated that both synergistic …

Development And Analysis Of A Nutrient Trading Program For The James River Watershed, Jennifer M. Reid

Dissertations, Theses, and Masters Projects

No abstract provided.

Tagging And Habitat Utilization Of Juvenile Summer Flounder, Paralichthys Dentatus, Richard Thomas Kraus

Dissertations, Theses, and Masters Projects

No abstract provided.

The Effect Of Phragmites Australis Invasion On Community Processes In A Tidal Freshwater Marsh, Michael Leadbeater Campana

Dissertations, Theses, and Masters Projects

No abstract provided.

Africa As A Regional And Global Source Of Atmospheric Gases And Particulates, Lawrence Mtetwa

Dissertations, Theses, and Masters Projects

The role of the continent of Africa as a source of gaseous and particulate emissions to the atmosphere is investigated in this study. Sources of gases and particulates from Africa include fossil fuel combustion, biomass burning, and biogenic soil emissions of nitric oxide. This study represents the first comprehensive database of gaseous and particulate emissions developed for the continent of Africa on a country by country basis and establishes the framework for country-by-country, assessment of greenhouse gases emissions as required by the Kyoto Conference on Global Warming, which was attended by representatives from more than 100 countries. Calculations of gases …

First Observation Of The Very Rare Decay Neutral Kaon(Long) Going To Electron Positron, Robert David Martin Iii

Dissertations, Theses, and Masters Projects

Brookhaven National Laboratory AGS Experiment 871 (E871) has carried out a search for the very rare, GIM and helicity suppressed decay of the long-lived neutral kaon into an electron-positron pair. This decay is predicted within the Standard Model to occur with a branching ratio of {dollar}(9.0 \pm 0.4)\times 10\sp{lcub}-12{rcub}.{dollar} Data were taken during the 1995 and 1996 AGS HEP running periods on the B5 beamline. A signal of (4 {dollar}\pm{dollar} 2) {dollar}K\sbsp{lcub}L{rcub}{lcub}0{rcub} \to e\sp+e\sp-{dollar} events is seen with a physics background expectation of 0.2 events. The ratio of the partial decay widths {dollar}\Gamma(K\sbsp{lcub}L{rcub}{lcub}0{rcub} \to e\sp+e\sp-)/\Gamma(K\sbsp{lcub}L{rcub}{lcub}0{rcub}\to\mu\sp+\mu\sp-){dollar} is determined to be {dollar}(1.3\sbsp{lcub}-0.6{rcub}{lcub}+0.8{rcub} …

Analysis Of Algorithms For Online Routing And Scheduling In Networks, Jessen Tait Havill

Dissertations, Theses, and Masters Projects

We study situations in which an algorithm must make decisions about how to best route and schedule data transfer requests in a communication network before each transfer leaves its source. For some situations, such as those requiring quality of service guarantees, this is essential. For other situations, doing work in advance can simplify decisions in transit and increase the speed of the network. In order to reflect realistic scenarios, we require that our algorithms be online, or make their decisions without knowing future requests. We measure the efficiency of an online algorithm by its competitive ratio, which is the maximum …

Improvements To The Color Quantization Process, Rance David Necaise

Dissertations, Theses, and Masters Projects

The presentation of color images on devices with limited color capabilities requires a reduction in the number of colors contained in the images. Color image quantization is the process of reducing the number of colors used in an image while maintaining its appearance as much as possible. This reduction is performed using a color image quantization algorithm. The quantization algorithm attempts to select k colors that best represent the contents of the image. The original image is then recolored using the representative colors. to improve the resulting image, a dithering process can be used in place of the recoloring.;This dissertation …

Stability Of Quark-Antiquark Models Of Mesons: A Study On The Validity Of The Spectator, Dirac, And Salpeter Equations, Michael Uzzo

Dissertations, Theses, and Masters Projects

Mesons are made of quark-antiquark pairs held together by the strong force. The one channel spectator, Dirac, and Salpeter equations can each be used to model this pairing. We look at cases where the relativistic kernel of these equations corresponds to a linear combination of scalar exchange and vector exchange. The vector exchange will be either the time-like component or the full four vector. The systems covered here are referred to as quasirelativistic, which means retardation, regularization, and form factors are not included. Since the model used in this paper describes mesons which cannot decay physically, the equations must describe …

Data Report: Pump Sampling And Sediment Analysis In Support Of The Sensor Insertion System Duck, N.C. April And October, 1997, Grace M. Massey, Carl T. Friiedrichs, Amo De Kruif, Daan C. Rijks

Reports

The objectives of this study were to (i) construct a pumping system, (ii) operate the system and collect samples of suspended sediment across the width of the surf zone during two major field experiments planned for the SIS in 1997, and (iii) analyze the resulting samples for sand concentration, sand size distribution, total percent sand, total percent mud, and organic content. The purpose was to provide a high quality data set of pump samples with which to later test the sensitivity of indirect measurements of suspended sand concentration to the presence of suspended mud. The response of OBSs is known …

Virginia Game Fish Tagging Program Annual Report 1997, C.M. Bain Iii, John A. Lucy, M. D. Arendt

Reports

The Virginia Game Fish Tagging Program (VGFI'P), a cooperative project of the Virginia Marine Resources Commission and the Virginia Institute of Marine Science (VIMS), set records for participation, fish tagged, and fish recaptured during its third year of operation.

Environmental Studies Relative To Potential Sand Mining In The Vicinity Of The City Of Virginia Beach, Virginia, Carl H. Hobbs Iii

Reports

Part 1: Benthic Habitats and Biological Resources Off the Virginia Coast 1996 and 1997 / G. R. Cutter, Jr. and R. J. Diaz

Part 2: Preliminary Shoreline Adjustments to Dam Neck Beach Nourishment Project Southeast Virginia Coast / C. S. Hardaway, Jr., D. A. Milligan, G. R. Thomas, and C. H. Hobbs, III

Part 3: Nearshore Waves and Currents Observations and Modeling / J. D. Boon

Part 4: Coastal Currents A. Valle-Levinson

Part 5: Benthic Foraminifera and Ostracoda from Virginia Continental Shelf / T. M. Cronin, S. Ishman, R. Wagner, and G. R. Cutter, Jr

In-Situ Impact Of Natural Sunlight And Tidal Action On The Composition And Toxicity Of Sediment-Associated Organic Pollutants, Robert Hale

Reports

Organic pollutants pose a haz.ard to living resources of the Chesapeake Bay and elsewhere. P AHs and other compounds present in creosote are major contaminants of concern. Polychlorinated terphenyls (PCTs), PCB-like compounds, have also been detected in high concentrations in sediments from several areas. Fates of these toxic compounds in-situ are poorly understood. In this study the impacts of physical processes operating in a tidal creek on the fate of creosote constituents (i.e. P AHs and heterocyclics) and PCTs were examined. Two representative sediments ( a coarse/low organic carbon (LOC) and a fine, high organic carbon (HOC)) were fortified with …

Tidal Freshwater And Oligohaline Benthos: Evaluating The Development Of A Benthic Index Of Biological Integrity For Chesapeake Bay, Robyn C. Draheim

Dissertations, Theses, and Masters Projects

No abstract provided.

Processes Affecting Macroalgal-Seagrass Dynamics In The York River, Virginia, Eva Machelor Bailey

Dissertations, Theses, and Masters Projects

No abstract provided.

The Parasite Fauna Of The Wreckfish, Polyprion Americanus, In The North Atlantic Ocean: Application To Host Biology And Stock Identification, Colleen Jill Fennessy

Dissertations, Theses, and Masters Projects

No abstract provided.

Vertebral Cartilage Of The Clearnose Skate, Raja Eglanteria: Development, Structure, Ageing, And Hormonal Regulation Of Growth, James J. Gelsleichter

Dissertations, Theses, and Masters Projects

Incremental marks formed in the vertebral cartilage of most sharks, skates and rays are widely used as indicators of age in elasmobranch growth studies. Such information is essential for fisheries management, thus vertebral ageing has become an invaluable tool for investigating elasmobranch life history. Unfortunately, lack of information on the processes that regulate vertebral growth and mineralization limit efforts to correlate episodic stimuli with increment production. to address this research need, this dissertation investigated these processes through a detailed study on the vertebral cartilage of the clearnose skate, Raja eglanteria. Histologic observations indicated that changes in appositional cartilage growth are …

Caribbean Spiny Lobster And Their Molluscan Prey: Are Top-Down Forces Key In Structuring Prey Assemblages In A Florida Bay Seagrass System, Martha Nizinski

Dissertations, Theses, and Masters Projects

Relative importance of predator-prey dynamics and several environmental variables in structuring gastropod and bivalve diversity and distribution was investigated in the subtropical seagrass and macroalgal community of Florida Bay, a highly productive system and primary nursery and foraging ground for finfish and invertebrate predators, including the numerically dominant Caribbean spiny lobster, Panulirus argus. The molluscan assemblage, a primary food source for P. argus in particular, is speciose (75 gastropod and 25 bivalve species) and a significant component of epifaunal and infaunal invertebrate assemblages within Florida Bay. Two experimental areas, located within separate basins and each comprised of two experimental sites, …

Physical Parameters Affecting Incubating Temperatures In Loggerhead Sea Turtles, Caretta Caretta, In Virginia, William Mason Jones

Dissertations, Theses, and Masters Projects

Detailed physical profile of eight transplanted loggerhead sea turtle, Caretta caretta, nests were obtained from Virginia and northeastern North Carolina and reburied in Back Bay National Wildlife Refuge (BBNWR), Virginia Beach, Virginia during the summers of 1987, '88, and '89 to determine if the physical location of the egg within the nest had an affect on sex determination. Transplanted nests were reburied in sandy substrate at a depth of 15-60 em on south facing dunes, and a Campbell Scientific data-logger logged synchronously environmental data. The following data were collected: temperatures at various locations within a nest, net absorbed radiation, ambient …

Oyster Reef Broodstock Enhancement In The Great Wicomico River, Virginia, Melissa Southworth

Dissertations, Theses, and Masters Projects

No abstract provided.

Wind Interaction With Buoyant Plumes On The Inner Continental Shelf, Sarah E. Rennie

Dissertations, Theses, and Masters Projects

The characteristics and effects of intrusions of estuarine outflow over the inner shelf were examined, based on hydrographic and meteorological observations obtained during the "Coastal Ocean Processes" (CoOP'94) field experiment located off the Outer Banks at Duck, North Carolina. The episodic presence of distinct low salinity water masses issuing from the Chesapeake Bay created an intermittent baroclinic coastal current along the North Carolina coast. Under low wind conditions, this current occupied the upper half of the water column within 9 km of the coast. The plume was bounded by a distinct southward-propagating front, a region offshore of high horizontal salinity …

Ecosystem Analysis Of Water Column Processes In The York River Estuary, Virginia: Historical Records, Field Studies And Modeling Analysis, Yongsik Sin

Dissertations, Theses, and Masters Projects

Analyses of EPA long-term datasets (1985--1994) combined with field studies and ecosystem model development were used to investigate phytoplankton and nutrient dynamics in the York River estuary. Analysis of the EPA dataset showed that algal blooms occurred during winter-spring followed by smaller summer blooms. Peak phytoplankton biomass during the winter-spring blooms occurred in the mid reach of the mesohaline zone whereas during the summer bloom it occurred in the tidal fresh-mesolialine transition zone. River discharge appears to be the major factor controlling the location and timing of the winter-spring blooms and the relative degree of potential nitrogen (N) and phosphorus …

A Probability Programming Language: Development And Applications, Andrew Gordon Glen

Dissertations, Theses, and Masters Projects

A probability programming language is developed and presented; applications illustrate its use. Algorithms and generalized theorems used in probability are encapsulated into a programming environment with the computer algebra system Maple to provide the applied community with automated probability capabilities. Algorithms of procedures are presented and explained, including detailed presentations on three of the most significant procedures. Applications that encompass a wide range of applied topics including goodness-of-fit testing, probabilistic modeling, central limit theorem augmentation, generation of mathematical resources, and estimation are presented.

A Search For Lepton Flavor Violation In The Neutral Kaon System, Christopher Henry Hoff

Dissertations, Theses, and Masters Projects

The conservation of separate lepton number is an ad hoc conservation principle in the Standard Model but several non-Standard Model theories allow violation of separate lepton number conservation. A very sensitive search for lepton flavor violation in the neutral kaon system, via the decay K0L→me , was undertaken by Brookhaven National Laboratory Experiment 871 (E871) during the 1995 and 1996 AGS HEP running periods. No K0L→me decays were observed and a single event sensitivity (SES) of 1.97x10-12 was achieved. This single event sensitivity corresponds to an upper limit on the branching fraction of BK0L→m e<4.53+/-0.21+/-0.46x 10-12 at a 90% confidence level.

Coherent Neutral Pion Photoproduction On The Deuteron, David G. Meekins

Dissertations, Theses, and Masters Projects

The differential scattering cross section for the process gd→dp0 was measured, as part of experiment E89-012 at Thomas Jefferson National Accelerator Facility. The experiment was performed in Hall C during the Spring of 1996 as the commissioning experiment for the Hall C cryogenic target. The High Momentum Spectrometer was used to detect the recoil deuteron and no effort was made to detect the p0 or its decay photons. The differential cross section was measured at a number of incident photon energies between 0.8 GeV and 4.0 GeV for the deuteron center-of-mass angles of 90?? and 136??. The data were found …

Wavelet-Based Digital Image Restoration, Viviana Sandor

Dissertations, Theses, and Masters Projects

Digital image restoration is a fundamental image processing problem with underlying physical motivations. A digital imaging system is unable to generate a continuum of ideal pointwise measurements of the input scene. Instead, the acquired digital image is an array of measured values. Generally, algorithms can be developed to remove a significant part of the error associated with these measure image values provided a proper model of the image acquisition system is used as the basis for the algorithm development. The continuous/discrete/continuous (C/D/C) model has proven to be a better alternative compared to the relatively incomplete image acquisition models commonly used …

The Role Of Adsorbed Oxygen In Secondary Emission From Metallic Substrates, Scott Gregory Walton

Dissertations, Theses, and Masters Projects

Low energy, ion- and photon-induced secondary electron and anion emission from metallic substrates has been investigated as a function of adsorbate coverage. Sodium positive ions (Na+), with kinetic energies up to 500 eV, and photons, with energies up to 23 eV, are utilized to initiate secondary emission. The principal adsorbate is oxygen with coverages ranging from none to a few monolayers.;For ion-induced emission, the secondary electron and negative ion absolute and relative yields from 302 stainless steel and polycrystalline tungsten (W) have been measured as a function of both impact energy and oxygen coverage. Additionally, the yields from a "technical" …